Investigating the genomic and biochemical effects of dalapon on antioxidant systems in zebrafish, Danio rerio

This research explored the effects of dalapon exposure on the expression of various genes, including cat, sod1, sod2, sod3a, sod3b, gpx1a, gpx3, gpx4a, gpx4b, gpx7, gpx8, gpx9, gstr, g6pd, and gsr, along with the activities of related antioxidant enzymes (AEs), such as CAT, SOD, GPX, G6PD, GST, and GR in zebrafish. Kidney and liver tissues were analyzed to assess oxidative stress levels. Results indicated that both the concentration of dalapon (25 and 50 ppm) and the duration of exposure had a significant effect on AE activities and gene expression. RT-PCR analysis suggested that changes in gene expression among dalapon-exposed zebrafish might indicate a rapid response to pesticide-induced stress. Moreover, the activities of CAT, G6PD, and GST increased in response to dalapon exposure at the specified concentrations. In contrast, prolonged exposure exceeding 72 h led to significantly higher malondialdehyde levels in liver and kidney tissues compared to the control group. These findings enhance our understanding of the role of antioxidant enzymes in oxidative stress and provide important insights for developing aquaculture breeding programs focused on improving fish stress tolerance. Furthermore, phylogenetic analysis and conserved gene synteny analysis confirmed that the antioxidant enzyme genes in zebrafish are orthologous to those found in other model organisms, such as medaka and stickleback. Consequently, these results could be beneficial for other vertebrate species.